Real-time colorectal polyp detection using a novel computer-aided detection system (CADe): a feasibility study.

BACKGROUND AND AIMS: Colonoscopy aims to early detect and remove precancerous colorectal polyps, thereby preventing development of colorectal cancer (CRC). Recently, computer-aided detection (CADe) systems have been developed to assist endoscopists in polyp detection during colonoscopy. The aim of this study was to investigate feasibility and safety of a novel CADe system during real-time colonoscopy in three European tertiary referral centers. METHODS: Ninety patients undergoing colonoscopy assisted by a real-time CADe system (DISCOVERY; Pentax Medical, Tokyo, Japan) were prospectively included. The CADe system was turned on only at withdrawal, and its output was displayed on secondary monitor. To study feasibility, inspection time, polyp detection rate (PDR), adenoma detection rate (ADR), sessile serrated lesion (SSL) detection rate (SDR), and the number of false positives were recorded. To study safety, (severe) adverse events ((S)AEs) were collected. Additionally, user friendliness was rated from 1 (worst) to 10 (best) by endoscopists. RESULTS: Mean inspection time was 10.8 ± 4.3 min, while PDR was 55.6%, ADR 28.9%, and SDR 11.1%. The CADe system users estimated that < 20 false positives occurred in 81 colonoscopy procedures (90%). No (S)AEs related to the CADe system were observed during the 30-day follow-up period. User friendliness was rated as good, with a median score of 8/10. CONCLUSION: Colonoscopy with this novel CADe system in a real-time setting was feasible and safe. Although PDR and SDR were high compared to previous studies with other CADe systems, future randomized controlled trials are needed to confirm these detection rates. The high SDR is of particular interest since interval CRC has been suggested to develop frequently through the serrated neoplasia pathway. CLINICAL TRIAL REGISTRATION: The study was registered in the Dutch Trial Register (reference number: NL8788).

Correlation between oropharyngeal pH-monitoring and esophageal pH-impedance monitoring in patients with suspected GERD-related extra-esophageal symptoms.

BACKGROUND: 24-hour esophageal pH-impedance (pH-MII) is not totally reliable for laryngopharyngeal reflux (LPR). Oropharyngeal (OP) pH-monitoring with the Dx-pH probe may detect LPR better. The correlation between these two techniques is not thoroughly established. Aim of this study is to examine the correlation between OP pH-metry and esophageal pH-MII monitoring. METHODS: Thirty-six consecutive patients with suspected gastroesophageal reflux disease-related extra-esophageal symptoms were evaluated using 24-h OP-pH and concomitant esophageal pH-MII monitoring. OP events were defined as: drop in pH below thresholds of 5.5, 5.0, 4.5, 4.0 or drop in pH of at least 10% from a running baseline. Temporal relationship between OP and esophageal reflux events and outcomes of the two tests were evaluated. KEY RESULTS: 2394 refluxes were detected by pH-MII; of these only 120 were detected also by OP Dx-probe. On the other hand, the proportion of OP-pH events which were temporally related to an episode of distal reflux ranged from 0% to 17%, depending on the proximal pH criteria used. In 8/36 patients both tests were pathological, while in 10/36 they were both normal; 14/36 patients had pathological OP reflux, but a normal pH-MII test; 4/36 patients had pathological pH-MII, but a normal OP reflux. CONCLUSIONS & INFERENCES: The correlation between OP pH-metry and pH-MII was weak. At present, the absence of a reliable gold standard for the diagnosis of LPR and the uncertain etiology of the pharyngeal pH alterations make it difficult to decide which is the most reliable technique for the diagnosis of true LPR.

GastroPanel® test for non-invasive diagnosis of atrophic gastritis in patients with dyspepsia.

AIM: Atrophic gastritis (AG), first step in the cascade leading to gastric adenocarcinoma, is related to Helicobacter pylori (H. pylori) infection. Currently, the gold standard for the diagnosis of AG is esophagogastroduodenoscopy (EGD) with histological examination of the biopsy specimens. However, since the latter are taken in random order and the distribution of AG is often patchy, histology is only representative of mucosal status. Considering this limitation, a test named GastroPanel®, that measures the blood concentrations of pepsinogen I and II, gastrin-17 and H. pylori antibodies, has been developed as a potential non-invasive biopsy. Aim of this study has been to assess the accuracy of GastroPanel® in patients with AG. METHODS: Forty-seven dyspeptic patients (24 males, mean age 52.2±9.3 years), in follow-up for antral or diffuse AG, were enrolled. All underwent at least two EGDs with random biopsies and blood collection for GastroPanel® parameters examination. RESULTS: Of the 47 patients, 16 (34.1%) had histological diagnosis of antral and 31 (65.9%) multifocal AG; 17 (36.2%) patients had mild and 30 (63.8%) had moderate-severe AG. H. pylori was detected in 39 (82.9%) and intestinal metaplasia was found in all patients. GastroPanel® showed 82.9% sensitivity for the diagnosis of AG and 53.8% for the diagnosis of H. pylori infection. The prediction of advanced atrophy was not sufficiently accurate, neither in patients with antral nor in those with multifocal AG. CONCLUSION: GastroPanel® can be useful for detecting patients with AG. However, it does not reflect the severity of atrophy.

Endoscopic mucosal resection in high- and low-volume centers: a prospective multicentric study.

BACKGROUND: Endoscopic mucosal resection (EMR) is an effective therapeutic technique well-standardized worldwide for the treatment of gastrointestinal neoplasm limited to the mucosal layer. To date, no study has compared technical and clinical differences based on the number of EMRs performed per year. This study aimed to compare EMR technical success, complications, and clinical outcome between low-volume centers (LVCs) and high-volume centers (HVCs). A total of nine endoscopic centers were included in the study. METHODS: This prospective study investigated consecutive patients with sessile polyps or flat colorectal lesions 1 cm or larger referred for EMR. RESULTS: A total of 427 lesions were resected in 384 patients at nine endoscopic centers. Males accounted for 60.4% and females for 39.6% of the patients. Most of the EMRs (84.8%) were performed in HVCs and only 15.2% in LVCs. All the lesions were resected in only one session. Argon plasma coagulation was performed on the margins of piecemeal resection in 15.7% of the patients in HVCs only. Complete excision was achieved for 98.6% of the lesions in HVCs and 98.8% of the lesions in LVCs. The complication rate was 4.4% in HVCs and 4.6% in LVCs (p = 0.94). Delayed bleeding occurred in 2.5% of the HVC cases and 3.1% of the LVC cases. Perforation occurred in 1.9% of the HVC cases and 1.5% of the LVC cases (p = 1.00). Recurrences were experienced with 15% of the lesions: 15.5% in HVCs and 14% in LVCs (p = 0.79). CONCLUSIONS: The study showed that EMR can be performed also in LVC.

European Society of Gastrointestinal Endoscopy (ESGE) Guideline: prophylaxis of post-ERCP pancreatitis.

Pancreatitis is the most common complication of endoscopic retrograde cholangiopancreatography (ERCP). Risk factors for post-ERCP pancreatitis (PEP) are both patient-related and procedure-related. Identification of patients at high risk for PEP is important in order to target prophylactic measures. Prevention of PEP includes administration of nonsteroidal inflammatory drugs (NSAIDs), use of specific cannulation techniques, and placement of temporary pancreatic stents. The aim of this guideline commissioned by the European Society of Gastrointestinal Endoscopy (ESGE) is to provide practical, graded, recommendations for the prevention of PEP.

Autoimmune pancreatitis: a challenging diagnostic puzzle for clinicians.

Autoimmune pancreatitis is a form of pancreatitis with autoimmune stigmata that may present as either focal or diffuse gland involvement. In focal forms, autoimmune pancreatitis shares demographic, clinical, biochemical and imaging features with pancreatic cancer. Since autoimmune pancreatitis is a benign disease and steroid therapy can rapidly resolve symptoms, improve radiological findings and avoid unnecessary surgery, the current clinical challenge is how to differentiate autoimmune pancreatitis from pancreatic neoplasia. Even though definitive diagnosis of the disease is difficult, several diagnostic criteria have been proposed and progress has been made in imaging studies. The management of this unique form of pancreatitis should, therefore, be handled in centres with knowledge of all aspects of the disease. This article briefly reviews clinical aspects of autoimmune pancreatitis with a focus on its diagnostic imaging and management.

Investigation of Oddi sphincter structure by optical coherence tomography in patients with biliary-type 1 dysfunction: a pilot in vivo study.

BACKGROUND: Type 1 sphincter of Oddi dysfunction is a clinical entity characterised by biliary-type pain, elevated liver biochemical tests, and common bile duct dilation. Sphincter fibrosis is a common finding in this type of dysfunction and may require in some cases a differential diagnosis with a malignant intra-papillary disease. Optical coherence tomography permits high-resolution, real-time imaging of the sphincter of Oddi microstructure by a probe inserted into the common bile duct through an ERCP catheter. No data exist on the evaluation of sphincter of Oddi fibrosis by optical coherence tomography during ERCP in vivo. OBJECTIVE: To assess the feasibility of optical coherence tomography investigation of the sphincter of Oddi structure and assess its potential for diagnosing type 1 sphincter of Oddi dysfunction. PATIENTS: Ten consecutive patients, five with biliary-type 1 sphincter of Oddi dysfunction and five with pancreatic head/mid-body adenocarcinoma not involving the papillary region, who underwent both endoscopic ultrasound and therapeutic ERCP, were investigated by optical coherence tomography immediately before biliary sphincterotomy or stenting. RESULTS: In all sphincter of Oddi dysfunction patients optical coherence tomography recognised a hyper-reflective intermediate, fibro-muscular layer, significantly thicker than in patients with non-pathological sphincter of Oddi (p<0.0001). CONCLUSIONS: Optical coherence tomography imaging recognised an increased thickness and reflectance of the fibro-muscular layer of the sphincter of Oddi, very likely determined by fibrosis, and was not time-consuming; it can be safely used during ERCP to confirm the diagnosis in difficult cases. Its use in clinical practice has one important limitation since it requires magnification in the post-procedure computer analysis to obtain images useful for diagnosis.

Optical coherence tomography in pediatric patients: a feasible technique for diagnosing celiac disease in children with villous atrophy.

BACKGROUND AND AIM: Celiac disease is a common condition with many atypical manifestations, where histology serves as the "gold standard" for diagnosis. A useful new technique, optical coherence tomography, can depict villous morphology in detail, using light waves. This study examined the correlation between the sensitivity and specificity of optical coherence tomography in pediatric patients undergoing esophago-gastro-duodenoscopy for the diagnosis of celiac disease. MATERIALS AND METHODS: A total of 134 children were prospectively enrolled, 67 with a serological suspicion of celiac disease (group 1) and 67 with negative histology for celiac disease (group 2). During a diagnostic esophago-gastro-duodenoscopy we acquired multiple images and films in the four quadrants of the second part of the duodenum, and biopsies were taken in the area where optical coherence tomography had been done. Three patterns of villous morphology were considered: pattern 1=no atrophy (types 0, 1 or 2 of the Marsh classification); pattern 2=mild atrophy (type 3a or 3b); pattern 3=marked atrophy (type 3c). RESULTS: The diagnosis of celiac disease was histologically confirmed in all 67 children with positive antiendomysium and/or antitransglutaminase antibodies. Optical coherence tomography correlated with pattern 1 histology in 11/11 cases, pattern 2 in 30/32 (93.8%) and pattern 3 in 22/24 (91.6%). Sensitivity and specificity were 82% and 100%. In the control group there was 100% concordance between optical coherence tomography and histology. The overall concordance between optical coherence tomography and histology in determining patchy lesions was 75%. CONCLUSION: Optical coherence tomography could be a helpful diagnostic tool in children with mild or marked villous atrophy for diagnosing celiac disease during upper gastrointestinal (GI) endoscopy, avoiding biopsies. However, duodenal biopsies are mandatory if the optical coherence tomography shows normal villous morphology in patients with positive antibodies.

Diagnostic yield of ERCP and secretin-enhanced MRCP and EUS in patients with acute recurrent pancreatitis of unknown aetiology.

BACKGROUND: Magnetic resonance cholangio-pancreatography (MRCP), endoscopic ultrasonography (EUS), and endoscopic cholangio-pancreatography (ERCP) are the most frequently employed second-step procedures to detect biliary and pancreatic abnormalities in patients with acute recurrent pancreatitis (ARP) of unknown aetiology. MRCP and EUS both give a better view of the bilio-pancreatic ductal system after secretin stimulation (MRCP-S, EUS-S). EUS also serves to identify changes in the pancreatic parenchyma consistent with chronic pancreatitis, at an early stage. However, no studies have compared MRCP-S, EUS-S, and ERCP in the diagnosis of recurrent pancreatitis. AIM: To prospectively compare the diagnostic yield of MRCP-S, EUS-S, and ERCP in the evaluation of patients with acute recurrent pancreatitis with non-dilated ducts, of unknown aetiology. METHODS: Forty-four consecutive patients with ARP were prospectively scheduled to undergo MRCP-S, EUS-S and ERCP, in accordance with a standard protocol approved by the institutional review board. Diagnoses such as biliary microlithiasis, congenital variants of the pancreatic ducts, chronic pancreatitis and sphincter of Oddi dysfunction were compared between the three procedures. The diagnosis of chronic pancreatitis was established according to ductal morphology by MRCP-S and ERCP, ductal and parenchymal morphology by EUS-S. RESULTS: The three procedures combined achieved a diagnosis that could have explained the recurrence of pancreatitis in 28/44 patients (63.6%). EUS-S recognized ductal and/or parenchymal abnormalities with the highest frequency (35/44 patients, 79.5%). Both MRCP-S and EUS-S were superior to ERCP for detecting pancreatic ductal abnormalities. EUS-S showed up pancreatic parenchymal changes in more than half the cases. Both EUS and MRCP secretin kinetics were concordant in identifying two cases with sphincter of Oddi dysfunction. CONCLUSIONS: The diagnostic yield of EUS-S in recurrent pancreatitis with non-dilated ducts and unknown aetiology was 13.6% and 16.7% higher than MRCP-S and ERCP respectively (although not significant), which both gave substantially similar diagnostic yields. In no case did ERCP alone find a diagnosis missed by the other two procedures. MRCP-S and EUS-S should both be used in the diagnostic work-up of idiopathic recurrent pancreatitis as complementary, first-line, techniques, instead of ERCP.

Endoscopic ultrasound-guided application of a new internally gas-cooled radiofrequency ablation probe in the liver and spleen of an animal model: a preliminary study.

BACKGROUND AND STUDY AIMS: In a previous study, a new flexible bipolar hybrid cryotherm probe was applied with success to the pancreas of a living pig. Here we evaluated feasibility, efficacy, and safety of its application to the porcine liver and spleen. MATERIAL AND METHODS: Ten applications to the liver and nine to the spleen were performed in 19 pigs. Power input (16-18 W) and simultaneous cooling with CO(2) (standardized pressure: 675 psi) as the cryogenic agent were investigated. Application time varied from 120 seconds to 900 seconds. The ablation area was measured by endoscopic ultrasound (EUS) after ablation (T0), and before euthanasia (T1). Gross pathology (T2) and histology after necropsy represented the gold standard. The interval from treatment to euthanasia was 1 or 2 weeks. RESULTS: For both organs the correlation between EUS and gross pathology was good (correlation coefficient R(liver) = 0.71; R(spleen) = 0.73). EUS tended to overestimate the area of the ablated zone. EUS observed a time-dependent ablation area: we demonstrated a positive trend of lesion size (T1) over time in liver tissue (R = 0.51 (P = 0.1)). In the spleen we found a clear correlation of lesion area T2 and application time (R = 0.75, P = 0.01). There were no complications. CONCLUSIONS: Selective EUS-guided transgastric cryotherm ablation of the liver and spleen in a pig model is feasible and safe. The new bipolar probe creates a time-dependent ablation area without any complications, and opens a field of new potential indications of RF-ablative therapies.

Endoscopic ultrasound-guided application of a new hybrid cryotherm probe in porcine pancreas: a preliminary study.

BACKGROUND AND STUDY AIMS: Open, laparoscopic, or percutaneous radiofrequency (RF) ablation of the pancreas is still dangerous, whereas endoscopic ultrasound (EUS)-guided ablation might reduce risk because it is less invasive and provides real-time monitoring. We aimed to demonstrate the feasibility of transluminal RF ablation and to evaluate the efficacy and safety of a new flexible bipolar ablation probe combining RF and cryotechnology. METHODS: 14 ablations were performed in 14 pigs. Energy input (16 W) and simultaneous cryogenic cooling with carbon dioxide (650 psi) were standardized. Application time range was 120 - 900 seconds. Ablation area was measured by EUS immediately after ablation (area T0), and before euthanasia (area T1). Macroscopic findings (area T2) and histological findings after necropsy served as gold standard. The interval from application to euthanasia was either 1 or 2 weeks. RESULTS: The correlation between EUS findings (area T1) and macroscopic appearance (area T2) was good ( R = 0.89). The correlation between the T2 ablation area and the application time showed a fitted ratio of 2.3 ( P < 0.0001) with a 1-week interval and 0.2 ( P = 0.01) with a 2-week interval. No pig died because of the procedure. Two pigs showed histochemical pancreatitis, which was clinically overt in one. Necropsy additionally revealed one burn to the gastric wall and four gut adhesions. CONCLUSIONS: Selective transluminal RF ablation of the pancreas under EUS control in a living pig model is feasible. The new flexible bipolar probe creates an ablation area with extent related to the duration of application, and with fewer complications than conventional RF ablation techniques.

Prospective multicenter quality assessment of endotherapy of biliary stones: does center volume matter?

BACKGROUND AND STUDY AIMS: To study the effectiveness of endoscopic treatment for biliary stones in a large case list of patients treated in units with different experience and different workloads in a region of northern Italy. PATIENTS AND METHODS: We prospectively studied 700 patients undergoing endoscopic retrograde cholangiopancreatography or sphincterotomy, in 14 units (> or < 200 examinations/year), for their first treatment of biliary stones. The difficulty of the examinations, the results in terms of clearance of the stones, and the late outcomes (24 months) were recorded. A questionnaire (GHAA-9modified) was administered 24 hours and 30 days after the procedure to measure patient satisfaction. RESULTS: There were six units with a heavy workload and eight with a light schedule. There were 176 (25.1 %) difficult examinations (Schutz grades 3, 4, and 5). Stones were found in 580 (82.9 %) and were cleared in 504 of these patients (86.9 %). No differences were observed in the clearance of stones for the different groups of difficulty and high- and low-volume centers. Over the 24-month follow-up period, 96 patients (13.7 %) complained of recurrent symptoms and 44 (6.3 %) had proof of stones. In all, 603 questionnaires were evaluable and more than 80 % of patients expressed satisfaction. CONCLUSIONS: Our findings confirm the effectiveness of endoscopic treatment of biliary stones. However, the number of patients with symptoms (13.7) after 24 months, with or without persistence of stones, was not insignificant. It is feasible to record patient satisfaction, and in this series patients stated they were satisfied. Criticism mostly concerned pain control and explanations provided before the examination.

Midazolam and pethidine versus propofol and fentanyl patient controlled sedation/analgesia for upper gastrointestinal tract ultrasound endoscopy: a prospective randomized controlled trial.

BACKGROUND AND OBJECTIVES: The aim of this prospective, randomized study was to compare the standard regimen of midazolam and pethidine administered by the gastroenterologist versus patient controlled sedation with a propofol-fentanyl mixture during upper gastrointestinal tract endoscopic ultrasonography. Our primary end-points were patient satisfaction and patient cooperation assessed by endoscopist. METHODS: Fifty-four consecutive patients, undergoing endoscopic ultrasonography, received sedation with midazolam and pethidine (Group M: n=27) or propofol and fentanyl (Group P: n=27). Group M: pethidine 0.7mg/kg midazolam 0.04mg/kg before examination; boluses of same drugs if the sedation was insufficient plus a sham patient controlled sedation analgesia; Group P: propofol 17mg plus fentanyl 15microg before examination and a patient controlled sedation analgesia pump containing 170mg propofol plus 150microg fentanyl injecting 0.5ml every time the patient pressed the button (no "lock out"). Boluses of 1ml of the same mixture if the sedation was insufficient. RESULTS: Group M: mean dosage of pethidine and midazolam 88.6 and 5mg, respectively. Group P: mean dosage of propofol and fentanyl 119.7mg and 106microg, respectively. Both groups were similar for duration and difficulty of the procedure, the grade of sedation (Observer's Assessment of Alertness/Sedation Score) and judgement by endoscopist and patient about cooperation and satisfaction. The only difference between groups was about the extra boluses administered during the procedure. CONCLUSION: This study demonstrated that a patient controlled sedation analgesia with propofol and fentanyl is an effective and safe technique for upper gastrointestinal tract endoscopic ultrasonography procedures and results in a high level of satisfaction both for patients and operator.